56 Mr. W. T. Blanford on the Animals 0/ Raphauhis, 



the exterior of the penultimate whorl^ opening to the air at the 

 extremity. I found this tube to be partly lined by a pexforated 

 process of the mantle, communicating internally, by means of a 

 passage beneath the shell-muscle, with a very small orifice inside 

 the air-chamber in the neck of the animal, aod thus affording 

 free access of the air to the pulmonary cavity, even when the 

 mouth of the shell is hermetically closed by the operculum. 

 The existence of this conformation cannot easily be observed 

 during life*, on account of the manner in which the mantle 

 lines the interior of the shell ; but after killing the animal in 

 hot water, and extracting it from the shell, the little free perfo- 

 rated process is distinctly seen, and is then about 2 millim. in 

 length, its dimensions having been, doubtless, much contracted 

 by the hot water. 



The genus Spiracuhm of Pearson was established upon the 

 species S. hispidum, P. By Dr. Pfeiffer that species has been 

 referred to Pterocyclos, to which it is certainly nearly allied, 

 although there appear to be good reasons for its generic separa- 

 tion. I have never had an opportunity of examining the animal 

 of S. hispidum ; but in the autumn of 1861 I met with a second 

 species of the same genus in the neighbourhood of Ava [S. ava- 

 num, mihi). This species is furnished with a small tube similar 

 to that in S. hispidum, opening at both ends, internally inside 

 the body-whorl, close to the suture and at a short distance be- 

 hind the peristome, and externally into the air, the short tube 

 on the exterior of the whorl being free and curved backwards. 

 The individual which I examined was just adult ; there was no 

 tubular process of the animal, but it was replaced by a deep 

 notch in the mantle corresponding to the perforation of the 

 shell. It is possible that, in older specimens, this notch may 

 become altered into a more or less perfect tube ; but, as the spe^ 

 cimen examined was full-grown, this is scarcely probable. 



The other tube-bearing genera with open tubes are Streptau- 

 lus, which can scarcely be considered as generically distinct from 

 Baphaulus, and Opisthoporus. I have not been able to examine 

 the animals of either of these. The tube in the aberrant genus 

 Alyc(Bus opens anteriorly into the body-whorl by a longitudinal 

 slit, as in the other genera ; but after running back along the 

 exterior of the suture for a greater or less distance, correspond- 

 ing with the inflated portion of the last whorl, it is closed at 

 the posterior termination. I have seen the soft parts of several 

 species, including the comparatively large A. umbonalis, Bens., 



* This is doubtless the reason that the tubular process of the mantle 

 was overlooked by so careful an observer as Mr. Benson, who, I believe, 

 confined his observations to the living animal. (See Ann. & Mag. Nat. 

 Hist. ser. 3. vol. iv. ]>. 94.) 



